Traveling outside side-striping spray gun

ABSTRACT

This disclosure relates to a spray gun, particularly one for applying a very thin, narrow side stripe to can bodies and other members. The spray gun basically includes a housing which has incorporated therein a reservoir to provide an immediately available supply of striping material. A spray orifice opens directly out of the reservoir and flow therethrough is controlled by a valve member which is mounted on a shaft for rocking movement therewith. The valve member is slidably mounted on the shaft and is preferably spring loaded against the housing so as to retain the same in tight contact therewith to maintain the seal between the housing and the orifice.

United States Patent Galitz Primary E.\'unu'nerRichard Av Schacher Attorney, Agent or Firm--Diller, Brown. Ramik &

[75] Inventor: Raymond F. Galitz, La Grange Wight Park. Ill.

[73] Assignee: Continental Can Company, Inc., [57] ABSTRACT New York, NY

This disclosure relates to a spray gun. particularly one i 1 Filed: 17, 1970 for applying a very thin, narrow side stripe to can bod- [211 Applg NO; 55,654 ies and other members. The spray gun basically in cludes a housing which has incorporated therein a reservoir to provide an immediately available supply of [52] US. Cl 239/586; 239/597 Striping materiaL A Spray Orifice Opens di out of [5 l] lnl. Cl 805i) 1/30 h reservoir and flow therethrough i Controlled a [58] Field Search 239/125- valve member which is mounted on a shaft for rocking 239/569 movement therewith, The valve member is slidably mounted on the shaft and is preferably spring loaded [56] References Cited against the housing so as to retain the same in tight UNITED STATES PATENTS Contact therewith to maintain the seal between the 1,142410 6/1915 Filbin 239/569 housing and the Orifice- 2,578.934 l2 195i Janssen 4 239 I25 3,606.l68 951971 Seaman ,i 239i597 4 Clams 5 Draw'ng figures 11 L r Tg r 3 r -b RETURN TRAVELING OUTSIDE SIDE-STRIPING SPRAY GUN This invention relates in general to new and useful improvements in spray guns, and more particularly to a spray gun which is particularly designed for applying a stripe of coating over a side seam of a can body. The spray gun is particularly designed for use with a hotmelt lacquer and similar coating materials and to be used in an environment wherein immediate start and stopping of the spray at rapid repeated intervals is required.

BACKGROUND OF THE INVENTION Experimentation has established the desirability of using a hot-melt lacquer formulation for the side striping of can bodies, thus eliminating the need for prolonged drying with heat which is necessary for lacquers containing solvents. It has also been determined that the conventional stationary spray gun, with can bodies being conveyed thereover at normal side-seamer speeds, produces a stripe too thick when using hot-melt lacquers even when the smallest practical gun orifice (0.002 inch X 0.375 inch) is used. In order to reduce the thickness of the side-stripe, it is proposed to provide a traveling gun, which gun will travel in the opposite direction of the can body travel at a speed that will result in the spray gun traversing the length of the can in about 1/10th of the time required for a stationary spray gun. This increase in speed, together with a traveling gun, makes complicated or impractical conventional electro-pneumatic gun triggering devices.

It is to be understood that since a traveling gun is a requirement, it can be readily operated mechanically as it passes a stationary cam. This cam can be adjustably positioned and adjustable for spray time so as to start and stop the spray in proper relation to the can length. The general details of such a spray system are disclosed in my copending application entitled Outside Side- Striping Device filed on even date herewith.

In view of the fact that can bodies travel at a high rate and it is now proposed to effect the side striping of can bodies in approximately 1/10th of the previously required time, it will be readily apparent that the valving of the spray gun must be of a type which can be quickly and readily actuated. It will also be apparent that inasmuch as the can bodies are to be side striped at a rate on the order of 500 can bodies per minute and higher, the valve mechanism of the spray gun must be one which can be repeatedly opened and closed.

SUMMARY OF THE INVENTION In accordance with this invention, there has been provided a spray gun which is particularly adapted to receive a hot-melt lacquer or like material which may be heated to a temperature on the order of 450"F. and which will be sprayed at a pressure on the order of 1,000 psi. In order to handle such a material, the spray gun of this application is provided with a valve which is directly mounted within the path of flow of the spray material and which valve is carried by a shaft for rocking movement therewith, the valve element having sliding contact with a surface of the spray gun housing and being movable from a position aligned with and closing the spray orifice to a position to one side thereof while remaining in contact with the housing and being sufficiently tightly engaged with the housing to effectively seal the spray orifice.

In order that the spray gun may be rapidly actuated, the controls therefor include a simple shaft which is mounted within the spray gun housing for rocking movement and which is provided exteriorly of the housing with a cam follower so that movement of the spray gun relative to a cam will effect the necessary rocking of the shaft to first open the spray orifice and then close the same.

A principal feature of the invention, as mentioned above, is the mounting of the valve element directly within the flow passage of the spray material. By slid ably mounting the valve element on the support shaft therefor, the pressure of the spray material serves to aid in the holding of the valve element in sealing contact with an arcuate surface of the housing. The spray orifice is directly formed in the housing through the menate surface and the valve element merely swings within the housing while being in sliding contact with the housing surface between a position overlying and closing the spray orifice and a position to one side of the spray orifice.

In accordance with this invention, it is also proposed that a small, but sufficient spray material reservoir be formed in the housing directly adjacent the spray orifice. It is within this reservoir that the valve element is mounted.

A further advantage of the spray gun is its compactness and light weight whereby it may be readily moved in accordance with the intended use thereof.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings:

IN THE DRAWINGS FIG. 1 is a schematic side elevational view of a traveling spray gun arrangement incorporating the spray gun of this invention.

FIG. 2 is an enlarged fragmentary vertical sectional view taken generally along the axis of the shaft of the spray gun and shows generally the construction thereof.

FIG. 3 is an enlarged longitudinal sectional view taken along the line 3-3 of FIG. 2 and shows further the details of the spray gun.

FIG. 4 is a horizontal sectional view taken along the line 4-4 of FIG. 3.

FIG. 5 is a sectional view similar to FIG. 3 and shows the valve element in its open position.

Referring now to the drawings in detail, it is to be understood that can bodies, such as the can body C illustrated in FIG. I are formed at a very rapid rate, that is on the order of 500 can bodies per minute and higher, on a conventional body maker. Each can body C is formed from a flat sheet which is rolled to a cylindrical configuration and the edges thereof are joined together to define a side seam which is schematically illustrated in FIG. 2 and identified by the numeral 8. The side seam 8 is illustrated as being of the welded type although it may be of other conventional construction.

The conventional body maker includes a horn 10 along which can bodies C are moved at regular intervals by means ofa conveyor chain I! having lugs 12 depending therefrom. The can bodies C are formed with their side seams 8 disposed lowermost and normally the metal in the area of the side seam is unprotected. Accordingly, in order to protect the side seams, it is necessary to provide a coating thereover in the form ofa side stripe.

As is more specifically disclosed in my aforementioned copending application, a spray gun, which is generally identified by the numeral 14, is moved in a direction opposite to the direction of movement of a can body C and is actuated by suitable cam means, generally identified by the numeral at a time when it is aligned with a can body to side stripe the side seam of the can body. The details of the spray gun 14 will be de scribed next followed by a general description of the operation thereof.

The spray gun 14, as is best shown in FIGS. 2, 3 and 4, includes a multiple piece housing which is generally identified by the numeral 16. The housing 16 is of a split construction and includes a pair of body members 17 and 18 which are releaseably secured together in sealed relation by a plurality of transverse fasteners 20. The body members 17 and 18 are internally relieved so as to define a large diameter reservoir 21 which includes port portions 22 and 23. A supply passage 24 opens into the port portion 22 and a return passage 25 opens into the port portion 23.

The reservoir 21 is open at its top and is closed by means of a cover plate 26 which overlies the body members 17 and 18 and which is secured thereto by means of fasteners 27. The underside of the cover plate 26 is relieved as at 28 to form a portion of the reservoir 21 with the relieved portion 28 having an arcuate surface 30 which will be described in more detail. A spray orifice 31 is formed in the cover plate 26 with the spray orifice 31 extending through the cover plate and in direct communication with the reservoir 21.

The body portions 17 and 18 are provided with aligned bores 32 and 33 which are also generally centered with respect to the reservoir 21. As is best shown in FIGS. 2 and 3, in each of the bores 32, 33 there is pressed a bushing 34. A shaft 35, which extends transversely through the reservoir 21 is rotatably journalled within the bushings 34 and projects outwardly beyond the body member 18.

An arm 36 is suitably secured to the projecting portion of the shaft and is provided at the opposite end thereof with a cam follower 37. Those portions of the shaft 35 disposed within the bushings 34 are provided with sealing rings 38 which are disposed in sealing engagement with both the shaft 35 and the bushings 34 so as to prevent the escape of coating material from the reservoir 21 through the bushings 34 alongside the shaft 35.

That portion of the shaft 35 disposed within the res ervoir 21 and between the bushings 34 is generally rectangular in cross section, as is shown in FIG. 3 and is identified by the numeral 40. A valve element, generally identified by the numeral 41 is slidably mounted on the shaft portion 40 for rocking or rotary movment therewith and for selectively sealing the spray orifice 31.

The valve element 41 includes a generally rectangu' lar body portion 42 which is provided with a central slot 43 of a size to snugly, yet slidably, receive the shaft portion 40. The valve element 41 also includes a sealing head 44 which is generally triangular in cross section and which terminates in a rounded nose 45, as is best illustrated in FIG. 5.

it is pointed out at this time that the arcuate surface 30 has a radius of curvature corresponding to the axis of rotation of the shaft 35. The nose 45 is also rounded to have the same radius of curvature and the same center as the arcuate surface 30.

it is to be understood that inasmuch as the valve element 41 is slidably mounted on the shaft portion 40 for radial movement and since the valve element is mounted within the reservoir 21 in which spray material is retained at a high pressure, the spray material will have a tendency to snugly retain the nose 45 of the valve element in sliding contact with the arcuate surface 30. When the nose 45 is aligned with the spray orifice, as shown in FIG. 3, it will block and seal the spray orifice 31 against the escape of spray material from within the reservoir 21. On the other hand, when the shaft 35 is rocked slightly in either direction, the spray orifice 31 will be uncovered, as is shown in FIG. 5, and the spray or coating material within the reservoir 21 will immediately flow outwardly through the spray orifice 31 as is schematically illustrated in FIG. 5.

In order that the spray gun 14 may he moved along a predetermined continuous path, it is necessary that it be supported in some suitable manner, either on a turret type support or, as more simply illustrated in the drawing, on a continuous chain, the chain being identified by the numeral 47. The spray gun 14 may be mounted in any desired manner although one of the easiest modes of mounting the spray gun is to provide a pair of support pins 48 on the support, such as the chain 47. The body member 17 is provided in the lower portion thereof with semi-circular cross sectional grooves 50 in which the support pins 48 seat. The body portion 18 terminates above the lower end of the body portion 17 and mounted beneath the body portion 18 is a clamp block 51 which is also provided with generally semi-circular cross sectional grooves, these grooves being identified by the numeral 52. The clamp block 51 is secured in place by means of a fastener 53 passing therethrough and being threaded into the lower part of the body portion 17, as is best shown in FIG. 2. When it is desired to release the spray gun 14 from the support, such as the chain 47, it is merely necessary to loosen up on the fastener 53 and to move the spray gun off of the pins 48.

Referring once again to FIG. 1, it will be seen that the cam means 15 includes a support piate 55 which is mounted for limited movement longitudinally of the horn 10- on support pins 56. The upper portion of the support plate 55 carries an upper guide element or cam 57. There is also mounted on the support plate 55 a lower guide element or cam 58 which is mounted for vertical movement on pins 60 carried by the support plate.

In the normal operation of the spray gun 14, a can body C will be moving from left to right at a constant speed. In a like manner, the spray gun 14 will be moving from right to left at a constant rate. The cam 58 will be positioned so that at the moment the spray orifice 31 becomes aligned with the leading edge of the can body C, the cam follower 37 will have ridden up the cam 58 sufficiently to move the valve element 41 to a position opening the spray orifice 31 to the interior of the reservoir 21 with there being spray through the spray orifice 31.

As the spray gun l4 rapidly moves past the cam 58, it will rapidly spray material over the side seam 8 of the can body C and when the spray orifice 31 reaches a point where it is substantially aligned with the trailing edge of the can body, the upper cam 57 will engage the cam follower 37 and force the valve element 41 to a position closing the spray orifice 31.

It is to be understood that the spray system may have incorporated therein a conventional type of detector (not shown) which will detect the existence of a can body. It is the desire that in the event there is no can body in position to receive the spray from the spray gun 14, spraying should not occur. Accordingly, the lower cam 58 is normally held in its operative position by a rod 61 which is vertically movable and which is carried by a suitable actuator 62 which is mounted on the support plate 55. The actuator 62, which may be in the form of a solenoid or a fluid motor will be operated in the absence of a can body to move the support 61 downwardly and move the lower cam 58 to a position where it will not engage the cam follower 37 and thus the spray gun 14 will not be actuated.

When the spray gun 14 is carried by a chain, such as the chain 47, in order that the spray gun will not vibrate or otherwise move undesirably as it passes through the spray area, it may be necessary to suitably guide the spray gun 14. Accordingly, the body portion 17 has on the lower portion thereof a lateral projection 65 (FIG. 2) which may be engaged in a suitable guideway (not shown).

No attempt is being made here to more specifically define the environment of the spray gun 14 and if a detailed description of the function of the spray gun 14 is desired, reference may be had to my aforementioned copending application.

Although only a preferred embodiment of the spray gun and environmental use thereof has been specifically disclosed herein, it is to be understood that minor variations may be made in the spray gun construction and the use thereof without departing from the spirit and scope of the invention, as defined by the appended claims.

I claim:

1. A spray gun comprising a housing, a supply passage in said housing, a spray orifice opening directly out of said supply passage, a shaft mounted for rocking movement within said housing, and a valve element mounted on said shaft within said housing for sealing engagement with said housing around said spray orifice, said supply passage including a reservoir within said housing, a wall of said reservoir being arcuately concentric to said shaft, said spray orifice opening through said arcuate wall, and said valve element being in wiping contact with said arcuate wall and scalable therewith around said spray orifice, said valve element being slidably mounted on said shaft for generally radial movement towards and away from said arcuate wall, and means within said reservoir urging said valve element against said arcuate wall.

2. The spray gun of claim 1 wherein said means urging said valve element against said arcuate wall is spray material pressure within said reservoir.

3. The spray gun of claim 1 wherein said means urging said valve element against said arcuate wall is a resilient member disposed between said shaft and said valve member.

4. The spray gun of claim 1 wherein said means urging said valve element against said arcuate wall includes spray material pressure within said reservoir and a resilient member disposed between said shaft and said valve member. 

1. A spray gun comprising a housing, a supply passage in said housing, a spray orifice opening directly out of said supply passage, a shaft mounted for rocking movement within said housing, and a valve element mounted on said shaft within said housing for sealing engagement with said housing around said spray orifice, said supply passage including a reservoir within said housing, a wall of said reservoir being arcuately concentric to said shaft, said spray orifice opening through said arcuate wall, and said valve element being in wiping contact with said arcuate wall and sealable therewith around said spray orifice, said valve element being slidably mounted on said shaft for generally radial movement towards and away from said arcuate wall, and means within said reservoir urging said valve element against said arcuate wall.
 2. The spray gun of claim 1 wherein said means urging said valve element against said arcuate wall is spray material pressure within said reservoir.
 3. The spray gun of claim 1 wherein said means urging said valve element against said arcuate wall is a resilient member disposed between said shaft and said valve member.
 4. The spray gun of claim 1 wherein said means urging said valve element against said arcuate wall includes spray material pressure within said reservoir and a resilient member disposed between said shaft and said valve member. 